As best as they could, the Orioles used the final seven weeks of last season to familiarize themselves with Anthony Santander, the promising Rule 5 draft pick who had spent months rehabilitating from a shoulder injury.

But at least on the field, he remained an enigma. One Orioles player, after Santander had been on the roster for a few weeks, forgot he was even there.

There's been no such anonymity this spring. Finally healthy and getting regular opportunities, a trimmed-down Santander is showing more than just promise as he's progressed from a roster requirement to a man the Orioles envision a legitimate role for.

"The guy came to us last year, he was hurt, played some last year — not a lot," manager Buck Showalter said. "I know he's moving better than I thought he would, and he's throwing. He's really engaged in the other side of the ball, which has been good to see. I'm so happy with the way he has approached things, his offseason. You can tell he's on a mission.”

With an opening at designated hitter thanks to a multi-week absence of Mark Trumbo to start the season due to a quadriceps strain, Showalter said, "It might be one of those years where he finds his way into a role.”

"That's usually how it starts," Showalter said. "A lot of unknown, whether the good things he's doing will continue up there, but what else do you want him to do — be bad?"

Santander certainly hasn't had to worry about that of late. Even after going 0-for-3 in the Orioles’ 4-2 win over the Detroit Tigers on Monday, Santander is batting .315 with four home runs and 16 RBIs.

That he could hit has never been a question. Before the Orioles took Santander in last year's Rule 5 draft, he slashed .290/.368/.494 with 20 home runs and 42 doubles in the Carolina League and was left unprotected off the Cleveland Indians' roster because of offseason shoulder surgery.

Once that healed, he hit .382 with a 1.119 OPS and five home runs in 16 minor league rehab games before joining the Orioles' roster in August and hitting .267 with three doubles in 30 at-bats.

Santander used the Arizona Fall League to make up some of the at-bats he missed, and entered the offseason on a mission.

"It was helpful because I was able to get a lot of at-bats there that I missed in the regular season," Santander said through team interpreter Ramón Alarcón. "I'm really appreciative of that, trying to get the at-bats, the plate appearances to get ready for the next season."

Browse photos from Orioles spring training in Florida in 2018.

He had plenty to work on this winter. With a major league role not guaranteed despite a holdover requirement of around six weeks on the major league roster to satisfy the carryover Rule 5 requirements from last season, Santander needed to show he could defend well enough in addition to bringing his bat into play.

“The main thing was trying to get my arm healthy, 100 percent healthy," Santander said. "That was one of the things. Another thing was I lost some weight, which I was working on, so that I could be quicker on the field, with the whole purpose of helping the team this upcoming season. ... I lost some weight with the idea to be more agile in the outfield, so I'm trying to take advantage."

He lost 15 pounds, he said, all without losing any of the power that made the Orioles so intrigued last season. His most recent home run, a go-ahead home run in the team's eventual 4-4 tie with the New York Mets on Friday in Port St. Lucie, was on a high-and-inside fastball near the handle of his bat that he muscled out to right field from the left side of the plate.

"Strong young man," Showalter said.

Once it was clear his bat remained what it was when the Orioles selected him two Decembers ago, the focus shifted to where they can best play him. Some internal evaluations of Santander had him profiled as a DH-only candidate at the time of his acquisition. But working with outfield coach Wayne Kirby and executive vice president Brady Anderson has led Showalter to give him time in right field and left field this spring, trying to get a feel for where he'll best fit.

While left field is where Trey Mancini will play regularly unless the team ends up without first baseman Chris Davis for any period of time, Santander's versatility in an outfield that could also include Colby Rasmus, Craig Gentry, and Alex Presley — all of whom can play all three positions — will allow plenty of daily maneuvering as the Orioles go through the early part of the season.

It's all a big departure for a player who last year, in a situation where he was asked to distinguish himself in difficult circumstances as a Rule 5 pick coming off an injury, did more blending into the background than standing out.

"The difference is this year I feel very well," Santander said. "I'm healthy [and have] total confidence in myself and my ability to help the team. ... [I'm] happy for the opportunity that I've been given. I feel confident with my teammates — they allow me to be myself, to have good at-bats, and go up there and have fun while at the same time help the team."